1. Field of the Invention
The invention relates to a device for generating and correcting a user program which is at the disposal of a machine control system and which is composed of a series of program steps which contain a function code and a space for a parameter value associated with at least one parameter of this function, the device comprising display means, function selection means, parameter selection means, and parameter value selection means. In order to provide insight into the field of the invention, an adapted introductory description will first be given hereinafter.
2. Description of the Prior Art
When it is assumed that a machine is a deterministic automatic device, a simple control panel in the form of a start button, a stop button and an emergency button would suffice as far as the man-machine interface is concerned. However, in practice machines are never fully deterministic, which is due on the one hand to the fact that the task of a machine can be modified to a limited extent by the operator, while on the other hand even the most reliable machine may incur defects. As a result, there is a need for a more extensive control panel which not only comprises the elementary buttons, but also a number of machine-specific buttons and which is also capable of providing the operator with error messages.
In most cases, the operator is not the sole user of the control panel. The panel should also be available for personnel performing adjustment and maintenance of the machine. This illustrates that the need exists for a panel which comprises a variety of buttons and which, moreover, can provide clear messages.
In view of the increasing demand for flexible production machines, these machines actually become substantially non-deterministic automatic devices. Consequently, the man-machine interface must be provided within an extra dimension. This is because in the case of flexible automation, the machine is rendered suitable for a new task by programming the desired behavior on site. This function should also be performed by the control panel. Therefore, the panel is usually referred to as a programming panel in this case.
In principle, the buttons and display means of such a panel could be connected directly to a computer, notably a mini-computer which nowadays in most cases forms part of said machine control system and which also controls the machine, and all software could be accommodated therein. Apart from the fact that this solution necessitates the use of an expensive interface, a substantial amount of communication is then required between programming panel and mini-computer.
If decentralization of the intelligence, i.e. data processing activity, were possible in such surroundings, the communication would be substantially reduced, so that the computer would be relieved and, moreover, the entire control would be clearer.
A further important aspect of the field of machine control systems consists in that the application possibilities of machine control systems may have an elaborate and complex structure. For each field of application of such a system, there will already be substantial numbers of functions which may be of importance. User programs then constitute long series of steps which relate to a wide variety of different functions and which contain the relevant values for the parameters thereof.